全文获取类型
收费全文 | 429篇 |
免费 | 29篇 |
国内免费 | 13篇 |
专业分类
儿科学 | 22篇 |
妇产科学 | 2篇 |
基础医学 | 19篇 |
口腔科学 | 14篇 |
临床医学 | 55篇 |
内科学 | 77篇 |
皮肤病学 | 4篇 |
神经病学 | 6篇 |
特种医学 | 178篇 |
外科学 | 11篇 |
综合类 | 40篇 |
预防医学 | 6篇 |
眼科学 | 4篇 |
药学 | 9篇 |
1篇 | |
肿瘤学 | 23篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 2篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 8篇 |
2009年 | 10篇 |
2008年 | 1篇 |
2007年 | 13篇 |
2006年 | 11篇 |
2005年 | 10篇 |
2004年 | 5篇 |
2003年 | 10篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 24篇 |
1997年 | 23篇 |
1996年 | 17篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 33篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 17篇 |
1988年 | 21篇 |
1987年 | 34篇 |
1986年 | 21篇 |
1985年 | 20篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 6篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1979年 | 1篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1971年 | 1篇 |
排序方式: 共有471条查询结果,搜索用时 15 毫秒
381.
382.
383.
Background: Implant supported restorations (ISRs) for the single implant may be cement retained or screw retained. Limited scientific evidence exists to support the superiority of a retention type for either implant or prosthetic success. The aim of this study was to assess preferences of Australian prosthodontists when restoring single implants. In particular, clinical practices for cross‐pin retained implant supported restorations for a single implant were investigated. Methods: A written questionnaire comprised of seven questions, some of which had multiple parts and of both open‐ and closed‐format, was sent to 124 Australian prosthodontists. The questionnaire asked recipients to identify: (1) their preference for retention choice when restoring a single implant; (2) the frequency of use; and (3) clinical practice when restoring a cross‐pin retained restoration. Results: Seventy‐seven per cent of respondents indicated that direct to fixture (DTF) retention was their first preference. DTF retention was also the most frequently employed restoration for single implants. Respondents indicated that cross‐pinned ISRs are employed to maintain retrievability or when DTF is not possible. The majority of respondents indicated they always or sometimes use a gasket with cross‐pin retained restorations, though gasket type varied. Thirty‐eight respondents (31%) indicated that they would never use a cross‐pinned retained restoration for a single ISR. Conclusions: Australian prosthodontists prefer, and more frequently restore single implants, using DTF retention. Queensland prosthodontists prefer cement retained ISRs. In comparison, cross‐pinned restorations tend to be the least favoured and least used retention type. In addition, variation in opinion exists regarding the need for a gasket and type of gasket to be placed. 相似文献
384.
Preparation of white cell-depleted red cells for 42-day storage using an integral in-line filter 总被引:1,自引:1,他引:1
RJ Davey ; RA Carmen ; TL Simon ; EJ Nelson ; BS Leng ; C Chong ; RB Garcez ; PR Sohmer 《Transfusion》1989,29(6):496-499
A new blood pack system for the preparation of white cell-depleted red cells was studied. The system is a modified additive-solution quadruple-unit blood pack that incorporates a cellulose-acetate fiber depth filter in-line between the AS-3 additive bag and the CP2D collection bag. Mean +/- SD white cell removal from 156 units processed under standard production conditions was 97.7 +/- 2.7 percent; residual white cells were 1.1 +/- 1.0 x 10(8) per unit. Red cell loss was 10.0 +/- 1.0 percent (n = 43). Mean platelet removal was 80.9 percent from units from which platelet concentrates were not prepared (n = 47). Microaggregates did not form during storage, and hemolysis of filtered red cells was lower than that of unfiltered controls. Filtered AS-3 red cells stored for 42 days had a 51Cr survival of 80.1 +/- 5.7 percent (mean +/- SD) as compared with 78.9 +/- 6.2 percent for unfiltered controls (n = 17). This in-line filter system provides white cell-depleted, microaggregate-free red cells that can be stored for 42 days. 相似文献
385.
To determine the influence of sperm parameters inseminated on the outcome of intrauterine insemination (IUI) in patients undergoing ovarian stimulation with clomiphen citrat (CC) or human menopausal gonadotropin (HMG) therapy, a retrospective review was performed for 2 years on data from the IUI program. 190 couples underwent a total of 268 IUI cycles in which CC or HMG was used for ovulation induction. The initial sperm concentration (mil/ml), motility (percent), preprocessing total motile sperm (TMS) count (million), fast motile sperm (percent) and postprocessing sperm concentration (mil/ml), motility (percent), TMS count, fast motile sperm (percent), sperm morphology, hypoosmotic swelling (HOS) scores, semen leuocytes, and bacteria were analyzed. 268 inseminations were followed by a pregnancy rate of 12% and couple pregnancy rate of 17%. On multivariable logistic regression analysis, total motile sperm (TMS) count, percent motility, and percent of fast motile sperm were independent prognostic factors of fertility. The impact of the preprocessing and postprocessing sperm parameters on pregnancy outcome after IUI was evaluated. There was a trend toward an increasing percent of conception with increasing TMS count, motility, and percent of fast motile sperm. The TMS count, motility and percent of fast motile sperm independently predict success with IUI. Patients with original sperm motility ≥30% had a higher cumulative pregnancy rate (74%) than patient with motility <30% (p < 0.005). Pregnancy rate increased 4 times with motility of ≥30%. 相似文献
386.
387.
CJM Lips EGWM Lentjes JWM Höppener RB van der Luijt FL Moll 《Hereditary cancer in clinical practice》2006,4(4):169-176
Paragangliomas are rare tumours of the autonomic nervous system and occur in sporadic and hereditary forms. They are usually benign and have a low mortality. However, they cause significant morbidity related to their mass effect. Genetic predisposition can occur within the familial tumour syndromes multiple endocrine neoplasia type 2 (MEN 2), von Hippel-Lindau (VHL) and neurofibromatosis type 1 (NF-1), or be due to mutations in genes specific to the development of paraganglioma only. Compared to sporadic forms, familial paragangliomas tend to present at a younger age and at multiple sites. Tumours should be diagnosed and resected as early as possible, as it has been shown that morbidity is related to tumour size. This article gives an overview of the current literature on the origin of the different forms of paragangliomas, DNA diagnosis, as well as biochemical and radiological screening guidelines. 相似文献
388.
389.
Katherine S Ruth Purdey J Campbell Shelby Chew Ee Mun Lim Narelle Hadlow Bronwyn GA Stuckey Suzanne J Brown Bjarke Feenstra John Joseph Gabriela L Surdulescu Hou Feng Zheng J Brent Richards Anna Murray Tim D Spector Scott G Wilson John RB Perry 《European journal of human genetics : EJHG》2016,24(2):284-290
Genetic factors contribute strongly to sex hormone levels, yet knowledge of the regulatory mechanisms remains incomplete. Genome-wide association studies (GWAS) have identified only a small number of loci associated with sex hormone levels, with several reproductive hormones yet to be assessed. The aim of the study was to identify novel genetic variants contributing to the regulation of sex hormones. We performed GWAS using genotypes imputed from the 1000 Genomes reference panel. The study used genotype and phenotype data from a UK twin register. We included 2913 individuals (up to 294 males) from the Twins UK study, excluding individuals receiving hormone treatment. Phenotypes were standardised for age, sex, BMI, stage of menstrual cycle and menopausal status. We tested 7 879 351 autosomal SNPs for association with levels of dehydroepiandrosterone sulphate (DHEAS), oestradiol, free androgen index (FAI), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, progesterone, sex hormone-binding globulin and testosterone. Eight independent genetic variants reached genome-wide significance (P<5 × 10−8), with minor allele frequencies of 1.3–23.9%. Novel signals included variants for progesterone (P=7.68 × 10−12), oestradiol (P=1.63 × 10−8) and FAI (P=1.50 × 10−8). A genetic variant near the FSHB gene was identified which influenced both FSH (P=1.74 × 10−8) and LH (P=3.94 × 10−9) levels. A separate locus on chromosome 7 was associated with both DHEAS (P=1.82 × 10−14) and progesterone (P=6.09 × 10−14). This study highlights loci that are relevant to reproductive function and suggests overlap in the genetic basis of hormone regulation. 相似文献
390.